Heat illness is associated with the cause of death of over 4,000 people annually in the United States. The human body operates with a core temperature between 36°-38° C. and if it is elevated, heat illness will occur. Heat illness can range from the minor (prickly heat) to the serious (heat exhaustion). Heat exhaustion can easily lead to heat stroke where a person will typically have a core body temperature of over 41° C., which can lead to death. The risk of heat illness, including heat exhaustion and heat stroke, are directly related to the temperature-humidity index. Temperatures greater than 80° F. and 80% humidity can lead to heat illness when combined with strenuous physical activity.
It is commonly known that the process of atomized water dispersed into the air provides a cooling effect. The atomization and dispersal of water into a fine mist can reduce the ambient temperature from 10° to 25° F. depending upon the relative humidity, and some outdoor misting systems claim temperature reductions of up to 35° F. In recent years, a number of water atomization or “misting” devices have been produced for pool and patio applications, restaurants, outdoor theme parks, zoos, greenhouses, and similar venues. Most of these applications utilize conventional water or plumbing lines to provide both a water source and the necessary system pressurization to create and disperse a cooling mist.
Many early atomization nozzles were actually designed for livestock and pesticide applications. This agricultural technology eventually was transferred and adopted into water atomization devices to provide a low energy cooling process for human comfort in various outdoor, non-climate controlled settings.
For many years, misting systems have been employed in outside commercial settings to provide a relatively cooler environment and continue to attract patrons even when daytime temperatures are at their highest. Mist cooling systems can be found in many patio restaurants and bars. They are a fairly standard fixture at amusement and theme parks such as the various Six Flags amusement parks, Disneyland, and Disney World. Misting systems are also seeing increasing popularity for residential use around patios in desert locations with very high temperatures and very low humidity such as Las Vegas and Phoenix, as well as other cities where high temperatures combined with medium to high humidity are common during summer months. Somewhat more sophisticated misting systems mated to a fan are used at outdoor events such as concerts and fairs.
When temperatures are high, outdoor entertainment businesses' patrons find other places to go. For example, the golfing industry suffers seasonal lows when the weather becomes hot. Conventional air-conditioning systems for golf carts and other open vehicles are impractical.
Many workers drive forklifts or otherwise engage in strenuous work outdoors. Other workers engage in strenuous work inside buildings without air conditioning systems or sufficient ventilation, such as warehouses. In addition to the inefficiencies associated with being uncomfortable while working, these workers are at risk of heat related illnesses. Misting systems attached to forklifts or other vehicles can substantially improve the attitude and productivity of the workers while reducing their exposure to the risks of heat-related illnesses. Other workers can benefit from personal, portable misting system.
Most active people also engage in physical activity outdoors lacking climate controlling air conditioning where temperatures are high enough for heat-related illness to develop. Personal, portable cooling systems also provide relief from the high heat stress these individuals can experience. Even if people are lounging in their backyard, a misting system can provide effective cooling to improve comfort.
To address the problem of heat-related discomfort and illnesses, misting devices have been developed that produce a cooling mist. Many of these misting devices are designed to be carried by hand, and lack the volume, and hands-free operation that some individuals prefer. Some designs require the introduction of pressurized air or water to provide a pressure source for forcing water through the atomization nozzles, or the device uses a battery-powered pump motor to force water through the atomization nozzle. These devices have inherent limitations as there use may be far from a pressurized water or compressed air source. Other variations require pumping air into the water reservoir to pressurize the system.
U.S. Pat. No. 5,622,056 and U.S. Pat. No. 5,535,951 disclose personalized atomization devices that are portable in nature. These devices have reservoirs divided into separate sealed sections by a flexible internal bladder, and quick-disconnect hose and nozzle couplings. These systems utilize the pressure of city water lines to fill an internal bladder while and have a secondary chamber pressurized with air that forces water out of an atomizer fitting. The disadvantages of these devices are that they incorporate the complex construction of a flexible bladder sealingly installed in a secondary containment reservoir and lack an effective distribution system for many activities.
U.S. Pat. No. 5,620,140 and U.S. Pat. No. 5,775,590 disclose a personal, portable cooling device utilizing a manual pumping chamber to achieve water atomization and provides for conductive cooling in addition to convective cooling, and allows for remote system pressurization. The disadvantages of this and similar devices are that they require separate operational steps to fill the reservoir and to compress the air in the reservoir and require the user to compress air in the reservoir and must do so by continuously pumping air into the reservoir by hand.
U.S. Pat. No. 6,371,388 and U.S. Pat. No. 6,216,961 disclose a misting device that includes an air flow directed toward a user. U.S. Pat. No. 6,371,388 claims a cylindrical misting device delivering a high velocity, laminar air flow with an atomizing nozzle discharging a mist into the air flow from a pressurized water tank. U.S. Pat. No. 6,216,961 claims a waist pack misting device delivering a 17 mph air flow at 18 inches from a fan directed toward a user's face with an atomizing nozzle discharging a mist into the air flow from a spray bottle. Both devices are designed to take advantage of the wind chill effect that occurs when air blows across a person's bare skin.
U.S. Pat. No. 5,613,371 discloses a system for providing water mist to the occupants of open vehicles such as golf carts. This system utilizes the power system of the vehicle to electrically pump water to atomizing nozzles. The system requires a relatively elaborate design of equipment, including an electrical water pump, accumulator, fuses, on/off switches, and a separate water tank. The disadvantages of these devices are that they are expensive, complex, and require electrical power to operate. Power supplied to accessory systems from electric carts is undesirable since it reduces the duration for which the vehicle can operate.
There is a need for a misting device that can passively produce a cooling mist that does not require an external pressurization or power source. Such a device would gain benefits of simplicity of design, use, and production. Such a device would not require any additional steps for use beyond filling the device with water.